Tread member for shoes



F. v. NUGENT TREAD MEMBER FOR SHOES Filed M arn 24, 1942 July 6, 1943.

v hatenied July i943 TREAD MEER FOB SHOES Frederick V. Nugent, Abington, Mass., assigner to B. B. Chemical filo., Boston, Mass., a corporation or Massachusetts This invention relates to shoe manufacture, and more particularly to tread members, such as outsoles and heel top lifts.

Vinyl resin in sheet form exhibits attractive possibilities as shoe material, but its utilization has involved shoemaking diiiiculties. Thus sheet vinyl resin does not constitute a satisfactory substance through which to pass stitches in Dreparing a tread member by a sewing operation, because of the tendency of the vinyl resin sheet to tear between the stitch holes. The disad-x vantages of using mechanical fastening means are obvious. On the other hand, in attempting to form shoe tread members by attaching vinylA resin sheet to leather by means of the usual commercial shoe cements, satisfactory adhesion for shoe tread purposes'has not been obtained. This is the case if it is attempted to use pyroxylin. rubber cement, rubber latex, or polymerized chloroprene for this p urpose.

An object of this invention is to provide a shoe treadrnember, such as an outsole or heel top lift, having a tread surface of sheet vinyl resin, and wherein the vinyl resin is securely and permanently attached to a leather layer.

In the accomplishment of the above and other objects, I have provided a shoe tread member having a tread surface of sheet vinyl resin and a backing layer of leather, and wherein a lm of chlorinated rubber is adhesively secured to said vinyl resin sheet, a nlm of polymerized chloroprene is adhesively secured to said chlorinated rubber, and the leather layer is adhesively secured to said polymerized chloroprene.

Conveniently the tread member may be prepared by roughing the attaching surface of the vinyl resin sheet, and depositing a nlm of chlorinated rubber thereon by applying thereto a solution of chlorinated rubber and permitting said solution to dry. A liquid dispersion or colloidal solution of polymerized chloroprene may then be applied to-the dried film of chlorinated rubber and to the attaching surface of the leather layer, and the solution permitted partially to dry. The vinyl resin sheet and the leather backing layer then may be pressed together with their polymerizecl chloroprene surfaces in juxta- 'Tornesit in a solvent therefor.

be applied progressively, as by passing the parts throughy Wringer rolls.

By the present invention I have provided a tread member wherein the tread surface and the backing layer are secured together firmly and closely Without gaping between the parts, and wherein the parts will remain secured together even when subjected to the stresses and conditions encountered in shoe Wear.

In the drawing,

Fig. i is a perspective view ci a shoe outsole according to the invention;

Fig. 2 is a fragmentary enlarged diagrammatic sectional View taken on line II--II of'Fig. 1;

Fig. 3 is a perspective View of a shoe heel top lift according to the invention;

Fig. 4 is a fragmentary enlarged diagrammatic sectional view taken on line IV-ZiV of Fig, 3;

Fig. 5 is a perspective view of a shoe having an outsole and a heel lift in accordance with this invention, the outsole being attached by'means .of aloft stitching; and

Fig. 6 is a fragmentary perspective view of a shoe having an outsole in accordance with this invention, the vinyl resin layer overlying stitches securing the outsole to the shoe.

The tread member contemplated by this invention has a sheet vinyl resin tread surface and a leather layer. The vinyl resin sheet material may comprise polyvinyl acetate, polyvinyl chloride, a copolymer of vinyl acetate and vinyl chloride, polyvinyl acetal or other suitable vinyl resin. The vinyl resin sheet material ordinarily contains a suitable plasticizer, such as dibutyl cellosolve phthalate, or dibutyl sebacate.

A preferred form of chlorinated rubber for use in this invention is that containing about 67% of chlorine and marketed under the trade' names Parlon or Tornesit by the Hercules Powder Company, Wilmington, Delaware. For the purposes of this invention the chlorinated rubber may be employed in the form of a solution of A suitable solution is one containing 15 to 20% by Weight of Tornesit dissolved in a solvent composed of equal parts of methyl ethyl ketone and toluene. The Tornesit itself may have a viscosity characteristic of from 5 to 100D centipoises. natively, the chlorinated rubber solution may contain dissolved vinyl resin and in such case the solution may contain about 10% by weight of Tornesit together with 10% by weight of low molecular weight vinyl resin (for example VYHF resin, manufactured by vCarbide and Carbon Chemicals Corporation) all dissolved in Alterequal parts of methyl ethyl ketone and toluene.

The polymerized chloroprene employed for the purposes of this invention is chloroprene (also known as chloro-2-butadiene-1,3) which has been partially polymerized and is plastic in the sense that it may be worked on the rolls of a rubber mill and compounded with other ingredients in a manner similar to that in which crude rubber is treated. Such plastic polymerized chloroprene may be cured or vulcanized" to a condition in which it is elastic rather than plastic and Vin which condition it resembles vulcanized rubber. This curin L is probably'a further ploymerizatiof the partially polymerizedclfiloroprene to a substantially fully polymerized condition rather than the addition of sulphur to the polymer such as is considered to occur in the vulcanization of rubber.

The polymerized chloroprene dispersions or colloidal solutions employed for the purposes of this invention may vary widely in composition but one which I have found very satisfactory is that disclosed in Macdonald Patent 2,163,609 and which is as follows.

' Grams Plastic polymerized chloroprene (containing 2% phenyl-beta-naphthylamine) 900 Wood rosin (FF) 45 Magnesium oxide (light calcined) 90 Zinc. oxide 45 Phenyl-beta-naphthylamine (stabilizer) 9 Benzene 1,690 Trichlorethylene 2,850 Sulphur 27 Du Pont accelerator #808 (btyraldehyde aniline condensation product) 12 In Figs. 1 and 2 there is illustrated a tread member in the shape of an outsole 2, which has a tread surface layer 4 composed of a. vinyl resin sheet. Adhesively secured to the vinyl resin layer 4 is a lm of chlorinated rubber 6. A film of polymerized chloroprene 8 is adhesively secured to the chlorinated rubber E, and a layer of leather I is adhesively secured to the polymerized chloroprene 8.

In preparing the outsole 2, a leather layer I0 of outsole leather stock, and a tread surface layer 4 of vinyl resin sheet, both of suitable size and shape, may be provided. The attaching surface I2 of the vinyl resin sheet 4 may be roughed in any suitable manner. To the roughed attaching surface I 2 may be applied by brush or other suit- Y able means, a chlorinated rubber solution such as hereinbefore described. This chlorinated rubber solution may be permitted to dry in the atmosphere for from about 15 minutes to an hour or longer, whereby a chlorinated rubber lm 6 is deposited upon and .adhesively attached to the attaching surface I2 of the vinyl resin sheet 4.

Following the securing of the chlorinated rubber film 6 to the vinyl resin sheet 4, a liquid dispersion or colloidal solution of polymerized chloroprene, such as described above, may be applied by brush or other suitable means over the chlorinated rubber film 6 on the vinyl resin sheet 4.

The attaching surface I4 of the leather layer I0 may be roughed in any suitable manner. To the attaching surface I4 may then be applied, by brush or in any other suitable manner, a liquid' dispersion or colloidal solution of polymerized chloroprene, such as hereinbefore described.

When the polymerized chloroprene cements on the chlorinated rubber illm 6 and on the attaching surface I4 of the leather layer I0 have dried to a condition in which they are adhesive to each other, which may require a period in the neighborhood of an hour, the vinyl resin sheet 4 and leather layer I0 may be pressed together with their polymerized chloroprene coated surfaces in juxtaposition to form a laminated structure embodying the polymerized chloroprene lm 8.

The vinyl resin sheet 4 and leather layer I0 may be pressed together in a hydraulic or other press at a pressure of abbut fifty pounds or more per square inch and for a time about five seconds or longer. Alternatively, the vinyl resin sheet 4 and leather layer I 0 may be passed through wringer rolls under a pressure of about fifty pounds or more per square inch.

In Figs. 3 and 4 I have shown a tread member in the shape of a heel top lift I6, which has a tread surface layer I 8 composed of a vinyl resin sheet. Adhesively secured to the vinyl resin layer i 8 is a film of chlorinated rubber 2U. A film of polymerized kchloroprene 22 is adhesively secured to the chlorinated rubber 20, and a layer of leather 24 is adhesively secured to the polymerized chloroprene 22.

Ihe heel top lift I6 may be prepared by providing a suitably shaped vinyl resin sheet I8 and a suitably shaped leather heel layer 24, and associating them with the chlorinated rubber film 28 and the polymerized chloroprene lm 22 in the manner described hereinabove with respect to the outsole 2.

Alternatively, the outsole 2 and heel top lift I6 might be prepared by securing together vinyl resin sheets and leather layers of indeterminate size in the manner described above and dyeing out or cutting out outsoles and heel top lifts therefrom.

In Fig. 5 I have illustrated a shoe 28 embodying an outsole 2 and heel top lift I6 according to this invention. Thus, the outsole 2 with the vinyl resin tread surface 4 is shown as stitched by aloft" stitching 28 to the welt 30. The heel top lift I6 is shown as secured to the lower lifts 32 of the heel by slugs or nails 34. Conveniently, the nails 34 may be driven below the surface of the vinyl resin layer I8, in order that the tread surface of the heel may be free from metal. Alternatively, the nails might be driven through the leather layer 24 prior to the attachment of the vinyl resin layer I8 thereto, and in such cases, the layer I8 might be secured to the layer 24 either before or after the attachment of the layer 24 to the heel layers 32. Furthermore, the top lift I6 might be secured t/J the other heel portions 32 by adhesive, rather than by nails, or in any other suitable manner.

In Fig. 6 is illustrated a shoe 36 having an outsole 38 according to this invention wherein the leather layer 40 extends the full length of the shoe but the vinyl resin layer 42 extends only over the forepart area of the outsole 38. 'Ihe chlorinated rubber film layer and the polymerized chloroprene nlm layer of the outsole 38 are not shown in enlargement. As illustrated, the leather layer 40 of the outsole 38 is secured to the welt 44 by stitches 48, and the vinyl resin layer 42 overlies the stitches 46.

The outsole 38 may be prepared in the manner described above so far as the central portion of the vinyl resin layer 42 is concerned but omitting the polymerized chloroprene lm around the marginal portions Iof the layer 42. Such marginal portions may then be raised during the operation of stitching the outsole to the welt d4 by means oi?l stitches d6, following which the polymerized chloroprene iilm may be incorporated at the marginal portions of the outsole 38 in the manner hereinbefore described. By this procedure the portion of the stitching d6 beneath the vinyl 'resin layer 42 is concealed. Alternatively, the vinyl resin sheet layer d2 may be secured to the leather layer d0 after the layer d0 has been secured to the welt 4B in the manner described above, and in such case the vinyl resin sheet layer 42 and the leather layer dll may be pressed together conveniently in a machine such as disclosed in Ballard Patent No. 2,047,185.

In Figs. 5 and 6, the leather layers I0 and d0, respectively, may of course be attached to the shoe uppers d8 and 50, respectively, by adhe-k Having described my invention, wha/t I claim as new and desire to secure by Letters Patent of the United States is:

1. A tread member for shoes comprising tread surface layer of vinyl resin, a film of chlorinated rubber/ adheslvely secured to said vinyl resin, a film of polymerized chloroprene adhesively secured to said chlorinated rubber, and a layer of leather adhesively secured to said polymerized chloroprene.

2. A shoe structure according to claimV 1 wherein the tread member is an outsole.

3. A shoe structure according to claim 1 wherein the tread member is a heel top lift.

, FREDERICK V. NUGENT. 

